Photopolymerizable composition containing a sensitized aromatic sulfonium compound and a cationacally polymerizable monomer

Claim 1

A photopolymerizable composition comprising: a. a cationically polymerizable monomer; b. an aromatic sulfonium compound of the following forumula: ##STR12## wherein R 1 , R 2 and R 3 are selected from the group consisting of aryl groups having 4 to 20 carbon atoms and alkyl radicals having 1 to 20 carbon atoms; wherein at least one of R 1 , R 2 and R 3 is aryl; wherein Z is selected from the group consisting of oxygen; sulfur; ##STR13## where R is aryl or acyl; a carbon-to-carbon bond; or ##STR14## where R 4 and R 5 are selected from the group consisting of hydrogen, an alkyl radical having 1 to 4 carbon atoms, and an alkenyl radical having 2 to 4 carbon atoms; and n is zero or 1; and X- is a halogen-containing complex anion selected from tetrafluoroborate, hexafluorophosphate, hexafluoroarsenate, and hexafluoroantimonate; and c. a sensitizing compound selected from the group consisting of: i. aromatic tertiary amines having the formula ##STR15## where Ar 1 , Ar 2 and Ar 3 are groups having 6-20 carbon atoms; Z is selected from oxygen; sulfur; ##STR16## a carbon-to-carbon bond; or ##STR17## where R 4 and R 5 are selected from hydrogen, alkyl radicals of 1-4 carbons, and alkenyl radicals of 2-4 carbons, and wherein n is zero or 1; ii. aromatic tertiary diamines having the formula ##STR18## where Y is a divalent radical selected from arylene and Ar 8 --Z--Ar 9 , where Z is as described above; Ar 4 , Ar 5 , Ar 6 , Ar 7 , Ar 8 and Ar 9 are aryl groups having 6-20 carbon atoms; and wherein n and m are zero or 1; and iii. aryl polycyclic compounds having at least three fused benzene rings and further having an ionization energy less than about 7.5 ev.